PROJECT SUMMARY Attention-Deficit/Hyperactivity Disorder (ADHD) is an early onset, heritable, prevalent and morbid neurobiological disorder. While ADHD typically onsets in early childhood, there are lengthy delays in the identification of the disorder frequently spanning many years, putting the children at elevated risks for developing serious adverse consequences. This calls for improved efforts in early identification of young children at risk for ADHD. Such efforts can help preventive interventions that mitigate the progression to the full disorder and its morbid consequences. One opportunity to help identify children at risk for ADHD is through studying the preschool aged offspring of parents with ADHD. This is so because 1) the most common age of children getting the clinical diagnosis of ADHD is in the early elementary school years, hence the preschool years could be an ideal target for the early identification of children at risk for ADHD, and 2) ADHD is highly heritable, and offspring of parents with ADHD are at increased risk to develop the disorder. We have preliminary data that certain clinical and neuroimaging characteristics could predict which child will develop ADHD. To this end, my proposed study will include clinical and neuroimaging assessments of 100 pre-syndromatic preschoolers (ages 4-6) at risk for ADHD by virtue of having a parent with ADHD, and 50 control preschoolers whose parents do not have ADHD. The children will be followed prospectively for two years to be monitored whether they develop ADHD diagnosis or not. Our central aim is to identify clinical indicators and neural biomarkers of the risk for ADHD that will foretell which preschool aged, pre-syndromatic children will develop the disorder. I am a board-certified Child and Adolescent Psychiatrist who has had a clinical and scientific focus on early identification of pediatric psychopathology. In my early career, I utilized existing longitudinal clinical data of an ADHD family study to evaluate clinical predictors of mood and anxiety disorders. I also conducted neuroimaging studies examining neural biomarkers cross-sectionally associated with clinical indicators of adversity in older children and adults. To further develop my expertise and become an independent investigator in the field of early identification, training in statistical analysis, neuroimaging, early childhood, and prospective data collection is necessary. I believe that by leading the proposed study titled, ?Neural and clinical biomarkers of risk for ADHD: A Focus on Preschoolers? which incorporates a longitudinal design involving preschool aged children assessing clinical and neuroimaging biomarkers of the risk for developing ADHD, along with a pointed training plan with didactics and mentorship that address my training goals, will help me establish independence.